1. Field of the Invention
The present invention is directed to a device for the actuating and unlatching of the shaft doors of an elevator. The device includes a first coupling member which is positioned on the landing or shaft door and a second coupling member which is positioned on the car door and can be brought into engagement with the first coupling member in the region of a floor or landing of a building. A latching mechanism is provided on the shaft door and on the car. When the car stops at a landing, the latch is in effective connection with the second coupling member in such a manner that the shaft door is unlatched and can be opened. This device opens or closes horizontally displaceable car and shaft doors simultaneously, when stopping at a landing, by means of a door drive mounted on the car.
2. Description of Background and Other Information
A device for the simultaneous actuation of the car and shaft doors of an elevator installation is illustrated in British Patent No. 587,984, and related U.S. Pat. No. 2,481,124, wherein an electromagnet which is positioned on the car actuates a coupling member which is movably mounted on the car door by a lever linkage. The coupling member has a wedge-shaped cross-section and is held in a disengaged position when the electromagnet is turned on. A fixed coupling member mounted on the shaft door includes a V-shaped groove, which is adapted to engage the wedge-shaped cross-section of the movable coupling member. When the car stops at a landing, the electromagnet is turned off, and both the coupling members come into engagement by means of spring force. In this case, the movable coupling member presses on a roller carried by a lever so that a rod fastened at the other end of the lever is upwardly displaced. The upper end of the rod is connected with a pawl which is thereby pivoted upwardly, so that the shaft door is unlatched and a control circuit is opened.
In another known device, disclosed in U.S. Pat. No. 1,876,438, an electromagnet is installed in the car door above a movable coupling member and is connected by a joint With the coupling member. The movable coupling member is held in a disengaged position by gravitational force. When the electromagnet is turned on, it comes into engagement with a fixed coupling member mounted on the shaft door. A further electromagnet mounted on the car is connected with a lever arrangement, in which a dog is articulately fastened. The dog lies against a roller which is carried by a lever, while the lever is connected with a pawl and arranged to be rotatable on the shaft door. At the beginning of the door opening movement, the further electromagnet is turned off so that the dog is moved downwardly and presses against the roller. In this case, the lever, and thereby also the pawl, carry out a pivotal movement so that the shaft door is unlatched and a control circuit is opened.
Noises and vibrations, which may be unpleasant to the passengers, in the above-described devices occur by the engaging and disengaging of the coupling members as well as by the electromagnets being switched on and off. In order to ensure unobjectionable engaging of the coupling members, both coupling members must lie opposite each other as exactly as possible, so that production and assembly must be highly accurate.